1. Field of the Invention
The invention relates to a data processing apparatus for executing data processing, such as detecting features of waveforms, based on an input signal, which is an output of an A/D conversion, and particularly to a data processing apparatus, which can prevent malfunction due to noise, an intrusion sensor using the data processing apparatus and an antitheft apparatus using the intrusion sensor.
2. Description of the Related Art
There are a large number of apparatus, which perform a certain control on the basis of a signal acquired from a certain sensor. For example, a vehicular security apparatus issues any alarm or reports, by radio, that an illegal intrusion into a prescribed place has occurred upon detecting, during arming, illegal door opening, an intrusion into the passenger compartment, vehicle vibration, breaking of glass, or the like. An intrusion sensor used in this security system detects whether or not an illegal intrusion into the vehicle has occurred by extracting a waveform variation due to a movement of an object (see JP 2004-142660A, for example).